Acquired aural cholesteatoma poses a unique procedural dilemma with regard to pathogenetic research and theory building. Because cholesteatoma spontane- ously occurs only in the poorly pneumatized human ear, its pathogenesis is specific to humans. Nonetheless, because of the ethical questions surrounding human experimentation, pathogenetic study has almost exclusively involved nonhuman subjects. Indeed, attempts have failed in almost all animal expe- riments except with the gerbil, and even here experimental designs have been improbable compared with human cholesteatoma. Cholesteatoma in the...